Participants randomized before amendment 2 will be stratified by stage of disease (stage IIIB/C, IVM1a, and stage IVM1b vs IVM1c) and v-raf murine sarcoma viral oncogene homolog B1 (BRAF) V600E (a mutation resulting in a substitution of glutamic acid for valine at codon 600) (mutation vs mutation not present). Participants randomized after amendment 2 will be stratified by stage of disease (stage IIIB/C and IVM1a vs stage IVM1b and IVM1c) and prior therapy (treatment naïve vs previously treated with systemic anticancer immunotherapy vs previously treated with systemic anticancer treatment other than immunotherapy).